A Storage Area Network (SAN) is known to be a network of storage disks, connecting multiple servers to a centralized disk storage pool. By treating all connected storage as a single resource, system maintenance is easier. A SAN can be centralized or distributed. A centralized SAN connects multiple servers to a collection of disks, whereas a distributed SAN typically uses one or more switches to connect nodes within buildings. Both types however use a centralized control structure, i.e. a client-server structure.
In a general Distributed Storage System (DSS), applications may determine the device on which data shall be stored. This is called “demanded storage target” herein. Often the user is requested to select a particular storage device. Intelligent ways of automatically selecting an individual storage device within a DSS are lacking.
Independent from DSS, storage devices may be duplicated for improved data security, availability or accessibility. The concept of cutting data into partitions and storing the partitions on different storage devices can also be applied within the single nodes of a DSS.